The end came with shocking severity. Just 15 days into the new year, with work on more than 400 public-sector contracts on the go, including the plagued Aberdeen bypass, it all came to a shuddering stop.

Carillion, the country’s second-largest construction company, informed the stock exchange that it had filed for liquidation, contracts were halted on a wet Monday, and more than 20,000 British jobs were in peril.

It had gone too far. No administrator was to be called in, there were no assets to sell, last-minute talks with the government over the weekend for a multi-million-pound loan had failed. It was over.

The country’s biggest public works contractor had gone spectacularly bust. There were debts of £6.9 billion and just £27 million left in the bank.

So, what went wrong? “It’s greed on stilts, pure and simple,” the Birkenhead MP Frank Field summed up. He was also the co-chair of a House of Commons inquiry quickly set up to look into the collapse.

Between 2009 and 2016, when Carillion filed its last accounts, it paid out £554m in dividends to its shareholders, while its income for the same period was just £594m, excluding the whopping sums the directors paid themselves in salaries and bonuses. Richard Howson, the chief executive at the time, took £7.2m in salary and pensions over that period.

Another major beneficiary was Richard Adam, the company’s financial director, until he left his post in December 2016, aged 59, to “spend more time with his family”. Three months later, on March 1, 2017, the first day he could cash in a first tranche of Carillion shares, he did so, making £534,000.

A second lot of long-term incentive shares, aimed at encouraging senior executives to stay loyal, were again cashed in on the first day they could be, May 8, earning Adam £242,000.

“Richard Adam went off to spend more time with his family with a golden goodbye from Carillion touching £2m,” Bob Wylie writes in his comprehensive and compelling account of the collapse in his book Bandit Capitalism. “Adam said when he left Carillion it was ‘healthy’ and was ‘operating in challenging markets but was managing these markets satisfactorily’.”

When Adams sold his shares the average share price was £2.12p, but when the company issued its first profits warning in July, less than two months after his second sale, the shares had slumped to 57p.

Fortuitous timing. Not according to Rudi Klein, chief executive of the Specialist Engineering Contractors’ Group, who remarked: “Adam telling us that he cashed the shares because they became due and nothing else is like the Russian poison crew telling us they went on holiday to Salisbury so they could see the cathedral.”

There was also the massive pension deficit which, as Adam was leaving the company, had reached £990m.

The chair of the Carillion pension fund trustees, Richard Ellison, told a Commons select committee that he believed that Adam viewed pension schemes as “a waste of money”.

Adam has strenuously denied making the statement or that it in any way represented his views.

In an email on May 15, 2018 to the Business and Work and Pensions Joint Parliamentary Committee, he demanded that the reference be removed from the report. The committee refused to delete it.

Carillion’s business had been built largely on public contracts and the mushrooming of PFI (public finance initiative) and PPP )public-private partnerships) which had been first introduced by the John Major Conservative government but really took off when Labour came to power under Tony Blair in 1997 when the Chancellor was Gordon Brown. It was a way of keeping public investment off the books, although it stored up interest and repayment charges for generations to come.

John Manzoni, who was permanent secretary for the Cabinet Office, told the parliamentary Carillion inquiry: “The entire PFI structure is to keep the debt off the public balance sheet. That is where we start.”

Brown also cut corporate regulation to the bone and made the Bank of England independent of government. He also slashed capital gains tax on assets from 40% to 10%, which resulted in a huge influx of international money, including from dodgy Russian oligarchs.

This was the essence of New Labour’s Third Way, or tax and transfer socialism as insiders called it.

The taxes on the booming market would pay for spending to create social reforms. So that in 2007, for instance, on the cusp of the crash which caused the banks “too big to fail” to fail, the banking industry was paying £68bn in tax, 14% of the total take.

Public works seemed like a bonanza for Carillion, and so they were to begin with.

But the margins in the construction industry are tiny and the company’s crazy pitches for contracts were often for less than cost, which they later tried to renegotiate.

When it went under the company held 423 PFI or PPP contracts, from part of the HS2 high-speed rail link to NHS provision. It was the main contractor in the London Crossrail project, to Network Rail. It had contracts with the Ministry of Defence, and maintaining prisons and providing contract cleaners for schools – anything, indeed, to keep cash rolling in.

By the middle of 2017 it was clear the company was in deep trouble. Its share price had plummeted to 57p and at least £500m was needed to stop up a gaping £845m hole in the books.

There were losses of £91m on the Aberdeen bypass project. The bid price was too low and it was a fixed-price contract, inadequately resourced and riven with problems no-one had factored in, like avoiding oil pipelines and water courses.

Losses of £83m on the Royal Liverpool University Hospital were also forecast, and £48m on the Midland Metropolitan Hospital. The £200m contract on public-sector prisons in England and Wales was losing £15m a year. Carillion, of course, had never run prisons before.

It all resembled some gigantic Ponzi scheme where the business could only continue by maintaining cash flow, whether or not the contracts would produce future profits and using the new income to service historic debt, coupled with aggressive accounting which put cash in the balance sheet in revenue and profits which hadn’t been made.

Among the accounting wheezes were counting profits from joint ventures as though they were Carillion’s alone, taking out short-term loans to be paid back after accounts were published to make net debt look better, concealing the true scale of borrowing, and securing advances on contracts and putting them through the books before profits had been earned.

Rachel Reeves MP, chair of the Commons inquiry, said: “I have always been a more avid reader of fiction than non-fiction, but I wonder whether the KPMG-audited accounts should be moved in the library to the fiction section.”

The final parliamentary report is no less damning of Carillion: “It presented accounts that misrepresented the reality of the business, and increased its dividend every year, come what may. Long-term obligations, such as adequately funding its pension schemes, were treated with contempt. Even as the company very publicly began to unravel, the board was concerned with increasing and protecting generous executive bonuses.

“Carillion was unsustainable. The mystery is not that it collapsed, but that it lasted so long.”

So what has changed? In the building industry almost nothing – still the pursuit of contracts at unfeasibly low pricing, and in accountancy the appetite for reform has waned, if it was ever there at all.

There are still four inquiries going on into the collapse, from the Pensions Regulator – the pension fund is owed up to £1000m – to the Financial Conduct Authority.

Rudi Klein, who is a barrister, served on the Government’s Carillion task force. He comments: “The question I pose is this. Has any public-sector decision-maker been hauled over the coals for letting contracts to Carillion? Answer: No!

“Two projects are worth mentioning – the Royal Liverpool and the Midlands Metropolitan Hospitals – ‘built’ by Carillion under PFI/PPP arrangements. Both hospitals suffered major delays and serious defects were discovered in the works at the Royal Liverpool. Yet, those who decided to let these contracts to Carillion have not been called to proper account.

“Until we have a robust system for holding to account those responsible for making key procurement decisions relating to large construction/infrastructure projects, the prospect of another Carillion-type fiasco is ever present.”

Don’t hold your breath.

Bandit Capitalism: Carillion And The Corruption Of The British State by Bob Wylie is published by Birlinn, £14.99.